Macrolithotypes control the pore-fracture distribution heterogeneity in coal, which impacts stimulation via hydrofracturing and coalbed methane (CBM) production in the reservoir. Here, the hydraulic fracture was evaluated using the microseismic signal behavior for each macrolithotype with microfracture imaging technology, and the impact of the macrolithotype on hydraulic fracture initiation and propagation was investigated systematically. The result showed that the propagation types of hydraulic fractures are controlled by the macrolithotype. Due to the well-developed natural fracture network, the fracture in the bright coal is more likely to form the “complex fracture network”, and the “simple” case often happens in the dull coal. The hydraulic fracture differences are likely to impact the permeability pathways and the well productivity appears to vary when developing different coal macrolithtypes. Thus, considering the difference of hydraulic fracture and permeability, the CBM productivity characteristics controlled by coal petrology were simulated by numerical simulation software, and the rationality of well pattern optimization factors for each coal macrolithotype was demonstrated. The results showed the square well pattern is more suitable for dull coal and semi-dull coal with undeveloped natural fractures, while diamond and rectangular well pattern is more suitable for semi-bright coal and bright coal with more developed natural fractures and more complex fracturing fracture network; the optimum wells spacing of bright coal and semi-bright coal is 300 m and 250 m, while that of semi-dull coal and dull coal is just 200 m.

中文翻译：

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各向异性煤层水力压裂行为分析及井网优化

大岩型控制煤中孔隙-裂缝分布的非均质性，这会影响通过水力压裂和储层中煤层气 (CBM) 生产的增产。在这里，利用微裂缝成像技术对每个大岩型的微地震信号行为进行了水力裂缝评估，并系统地研究了大岩型对水力裂缝起裂和扩展的影响。结果表明，水力裂缝的扩展类型受宏观岩型控制。由于天然缝网发育良好，亮煤中的裂缝更容易形成“复杂缝网”，而“简单”的情况往往发生在暗煤中。水力压裂差异可能会影响渗透性路径，并且当开发不同的煤宏观岩型时，井的产能似乎不同。因此，考虑到水力压裂和渗透率的差异，利用数值模拟软件模拟了煤岩学控制的煤层气产能特征，论证了各煤体宏观岩型井网优化因素的合理性。结果表明，方形井网更适用于天然裂缝不发育的暗煤和半暗煤，而菱形和矩形井网更适用于天然裂缝较发育、压裂裂缝较复杂的半亮煤和亮煤。网络; 光亮煤和半光亮煤的最佳井距为300 m和250 m，